Kenneth Branagh is teasing the return of "old friends'' in his planned sequel to "Murder on the Orient Express.''

Branagh is expected to both direct and reprise his role as the fancifully mustachioed lead character Detective Hercule Poirot in "Death on the Nile,'' another mystery based on an Agatha Christie novel, which screenwriter Michael Green will return to adapt.

Branagh says he's excited to gather an ensemble cast that could possibly include bringing back some "old friends'' to explore "primal human emotions'' like "obsessive love and jealousy and sex'' that make for a "very dangerous atmosphere.''

The tense whodunit "Murder on the Orient Express'' featured an all-star cast including Johnny Depp, Daisy Ridley, Judi Dench, Penelope Cruz and Michelle Pfeiffer. It was a global hit after its release in early November. Branagh says he was glad to see audiences responding to his quirky portrayal of Poirot and looks forward to seeing how that will evolve in the sequel.

"One of the things that I liked - really loved doing here that the audience responded to was that Hercule Poirot, for all his intellectual power, got dragged into it, got dragged into feeling it. And I think it's a hell of a trip, that trip down the Nile. So I think it would be great to see how he, how his heart, responds to that kind of intensity,'' he said.

With a wealth of source material to draw from, Branagh also endorses the idea of a Poirot-slash-Christie "cinematic universe'' - the popular term for a series of interlocking films that bring various characters together.

"I think there are possibilities, aren't there? With 66 books and short stories and plays, she - and she often brings people together in her own books actually, so innately - she enjoyed that,'' he says. "You feel as though there is a world - just like with Dickens, there's a complete world that she's created - certain kinds of characters who live in her world - that I think has real possibilities.''

However, Branagh says he hasn't exactly floated that idea with any of the brass at 20th Century Fox.

"I bet they've been thinking about it though,'' he says.

"Murder on the Orient Express'' will be released on home video in the coming months. "Death on the Nile'' is in the early stages of pre-production.